(1) Field of the Invention
The present invention relates generally to precision alignment machines and mechanisms. More particularly, this invention relates to a compliant mechanism enabling relative movement between a stage portion and a support structure to be controlled with a relatively high degree of accuracy and precision with up to six degrees of freedom.
(2) Background Information
There is a growing need for fine motion control and positioning at meso, micro, and nano scales. Examples include active alignment of components in fiber optics packages, x-y stages with nanometer level resolution, and machine elements for meso- and micro-scale machinery.
Culpepper, in U.S. patent application Ser. No. 10/005,562, filed Nov. 8, 2001, entitled “Apparatus and Method for Accurate, Precise, and Adjustable Kinematic Coupling”, (the ‘562 patent’) which is fully incorporated herein by reference, discloses an adjustable kinematic coupling in which one or more of the kinematic elements (e.g., balls and grooves) may be rotated about or translated along an axis thereby effecting a relative movement between two components. The coupling is well suited for applications where alignment with nanometer/microradian accuracy and precision (i.e., repeatability) and/or where controlled adjustment of the relative position of the coupled components is required.
An alternate approach to fabricating machines requiring fine motion control and positioning has employed the use of compliant mechanisms, and in particular monolithic compliant mechanisms. These compliant mechanisms, however, have typically been planar in nature, having the ability to control at most two translational degrees of freedom and one rotational degree of freedom (i.e., x, y, and θz). Examples include a rotational flexure stage for positioning a wafer relative to a microlithography projector disclosed by Barsky in U.S. Pat. No. 5,083,757, entitled “Rotational Flexure Stage”; a precision in plane (i.e., x, y, and θz) stage for optical components disclosed by Hale in “Principles and Techniques for Designing Precision Machines”, Ph.D. Thesis, M. I. T., Cambridge, Mass., 1999, p. 184; and a flexure-hinge guided motion nano-positioner disclosed by Elmustafa, et al. in “Flexural-hinge Guided Motion Nano-positioner Stage for Precision Machining: Finite Element Simulations,” Precision Engineering, 2001, vol. 25, pp. 77–81.
Next generation applications (e.g., fiber optic alignment) will likely require compliant mechanisms capable of providing high resolution (i.e., nanometer/microradian) position control with six degrees of freedom (i.e., x, y, z, θx, θy, and θz). Therefore there exists a need for new and improved flexures and/or compliant mechanisms that may be suitable for next generation applications.